Background: Substance use disorders (SUD)-drug use illnesses consistent with abuse or dependence of a range of substances-are common and costly mental health conditions among Veterans. Research has demonstrated that women differ from men in their patterns of SUD and in their use of services and determinants of treatment and outcomes. Although the emphasis of SUD care in the VA has been on the men who make up 96% of Veterans in SUD treatment, women Veterans represent a particularly vulnerable group with distinct needs and barriers to treatment. Women Veterans have higher rates of other psychiatric conditions, including PTSD, military sexual trauma (MST), bipolar/psychotic disorder, and mood disorders than do their male counterparts, and the occurrence of concomitant PTSD or MST requires assessing and accommodating women's needs in a private and safe SUD treatment environment. Despite VA requirements for gender aware care, most VA providers outside of women's health clinics have little or no experience delivering services to women Veterans. Women Veterans may have difficulty in the predominantly-male VA treatment environment. Purpose: The goal of the proposed CDA project is to develop the foundational evidence needed to improve women Veterans' access to optimal, gender-sensitive SUD care. To accomplish this goal, I will examine patient, provider, and organizational factors that foster or hinder the delivery of appropriate and effective care for women Veterans using mixed methods. Methods: The proposed CDA research plan will comprise 3 separate projects. The first, a secondary analysis of linked organizational- and patient-level data, will describe the patterns and determinants of women's SUD treatment involvement (initiation, engagement, and pharmacotherapy) and patient outcomes across VA facilities. The second will include the development and administration of the first survey of the organizational structure of women Veterans' VA SUD care. The survey data will be linked to patient-level data to determine the impact of women's SUD treatment structure on women veterans' treatment involvement and patient outcomes. The third project will be an in-depth qualitative study to learn from women VA SUD patients their experiences with VA SUD care and their perceptions of treatment barriers, preferences, and needs. The proposed CDA career plan builds on my strong epidemiology and biostatistics training while ensuring education, training and mentorship in the use of VA data sources, health services research design, the theory of substance use disorder, gender issues in mental health, qualitative research, organizational survey design, and implementation science. Conclusions: Providing patient-centered, gender-sensitive care for women Veterans with SUD is a VA goal, but there are fundamental information gaps on where and how women access SUD care in the VA. Moreover, little work has been done to determine the features of care that can best address women Veterans' specific needs and treatment barriers. The proposed research will address these knowledge gaps, paving the way to subsequent target efforts to provide women Veterans optimal, gender-sensitive SUD care.